bcbert-4 Posted July 8, 2012 Share Posted July 8, 2012 Looking for some insight. My primary production class gun has been a S&W M&P9 with a KKM barrel installed. I have been loading for this gun for about a year with fantastic results. My standard load for it is: Berry's 147gr VV N320 3.6gr C.O.L. 1.1500 I make PF 130 all day long with a SD in the low teens. I have been very happy with this load and it has been consistent. I recently picked up a S&W M&P9 PRO and have also added a KKM barrel to it. With the same load, my results are all over the place. Velocity ranges from 900 fps down to 790 fps and SD is quite high. I thought it might be the batch of reloads, but they were right on the money when I fed them through the standard size M&P over the chrono. Any thoughts on how to adjust the load for the PRO series gun? Link to comment Share on other sites More sharing options...
Glockman1000 Posted July 8, 2012 Share Posted July 8, 2012 Just a thought, try using the original Pro barrel with your load & see what kind of results you get. You could at least eliminate one thing to check. Maybe the chamber in the KKM is different from what is in your M&P Standard KKM barrel. It may need a different crimp or OAL, or even a bump in powder charge. Maybe the barrel just needs to broken in a bit more. Link to comment Share on other sites More sharing options...
L3324temp Posted July 8, 2012 Share Posted July 8, 2012 (edited) I would give the stock barrel a try as suggested. Also try the stock spring if you have changed it for a lighter one. Some people report some of these guns unlock early, perhaps that is what yours is doing. Are you getting vertical stringing? Edited July 8, 2012 by L3324temp Link to comment Share on other sites More sharing options...
bcbert-4 Posted July 8, 2012 Author Share Posted July 8, 2012 (edited) I would give the stock barrel a try as suggested. Also try the stock spring if you have changed it for a lighter one. Some people report some of these guns unlock early, perhaps that is what yours is doing. Are you getting vertical stringing? I haven't seen any evidence of vertical stringing. I will try the original barrel and stock spring. Hopefully tomorrow or tuesday. Thanks for the help. Edited July 10, 2012 by bcbert-4 Link to comment Share on other sites More sharing options...
bcbert-4 Posted July 10, 2012 Author Share Posted July 10, 2012 Here is the latest data. I was using a 13# spring before, went back to the stock spring and guide rod which is 15 or 16 # Load # 1 S&W M&P9 PRO - Stock Barrel Berrys 147gr 9mm Federal Primer VV N320 3.6 GRN COL 1.142 HI 929 FPS / Lo 876 FPS / AVG 902.9 / ES 62.7 / SD 15.6 / AVG PF 132 Load #2 S&W M&P9 PRO - Stock Barrel Berrys 147gr 9mm Federal Primer VV N320 3.7 GRN COL 1.142 HI 930 FPS / Lo 865 FPS / AVG 902.9 / ES 64.9/ SD 16.7 / AVG PF 133 Load #3 S&W M&P9 PRO - KKM Barrel Berrys 147gr 9mm Federal Primer VV N320 3.6 GRN COL 1.142 HI 937 FPS / Lo 818 FPS / AVG 878 / ES 119.4 / SD 36.7 / AVG PF 129 Load #4 S&W M&P9 PRO - KKM Barrel Berrys 147gr 9mm Federal Primer VV N320 3.7 GRN COL 1.142 HI 921 FPS / Lo 838 FPS / AVG 871 / ES 83.1/ SD 18.5 / AVG PF 128 Any thoughts? what worries me with the KKM barrel is the randomness of the velocities and the shots that end up below min PF. Link to comment Share on other sites More sharing options...
yoshidaex Posted July 10, 2012 Share Posted July 10, 2012 (edited) same head stamp or mixed brass? New brass, once fired or unknown? Edited July 10, 2012 by yoshidaex Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted July 10, 2012 Share Posted July 10, 2012 How is accuracy in each gun? Sounds like, if everything else is identical, you have a "bad barrel" from KKM?? They stand behind their product? Link to comment Share on other sites More sharing options...
bcbert-4 Posted July 10, 2012 Author Share Posted July 10, 2012 same head stamp or mixed brass? New brass, once fired or unknown? All Fed Brass. All once fired by me. Link to comment Share on other sites More sharing options...
bcbert-4 Posted July 10, 2012 Author Share Posted July 10, 2012 How is accuracy in each gun? Sounds like, if everything else is identical, you have a "bad barrel" from KKM?? They stand behind their product? Accuracy is seems to be fine, but then again all the shooting in the KKM pro barrel has just been over the chrono so far. Link to comment Share on other sites More sharing options...
L3324temp Posted July 11, 2012 Share Posted July 11, 2012 Maybe try a different brand/weight bullet or adjusting the COL. Some guns just don't like some loads. Link to comment Share on other sites More sharing options...
yoshidaex Posted July 11, 2012 Share Posted July 11, 2012 New barrel? Shoot it for a 1000 rounds or so. Re chrono to see if the velocities stabilized. Link to comment Share on other sites More sharing options...
yoshidaex Posted July 11, 2012 Share Posted July 11, 2012 Also keep track of the way it prints on paper at a set distance. Link to comment Share on other sites More sharing options...
simar Posted July 11, 2012 Share Posted July 11, 2012 Before you shoot a ton more thru the barrel, try contacting kkm and see what they have to say. Link to comment Share on other sites More sharing options...
CocoBolo Posted July 11, 2012 Share Posted July 11, 2012 (edited) Just to eliminate some of the variables go to WalleyWorld buy a couple boxes of Win White Box and shoot 20 rounds in each barrel over the crono, same day, light temp etc. This takes the reloads out of the list of things to check. If you get poor results with the KKM then give them a call. I have 3 9 major open guns 2 with the cheap clark barrels and one with a schueman barrel all new about the same time. The 5" clarks are faster than the 5.4" Schueman by 20 fps, same ammo, same time of day, same crono, all things equal. I don't consider the schueman defective, just not as fast. Edited July 11, 2012 by CocoBolo Link to comment Share on other sites More sharing options...
bcbert-4 Posted July 11, 2012 Author Share Posted July 11, 2012 Just to eliminate some of the variables go to WalleyWorld buy a couple boxes of Win White Box and shoot 20 rounds in each barrel over the crono, same day, light temp etc. This takes the reloads out of the list of things to check. If you get poor results with the KKM then give them a call. I have 3 9 major open guns 2 with the cheap clark barrels and one with a schueman barrel all new about the same time. The 5" clarks are faster than the 5.4" Schueman by 20 fps, same ammo, same time of day, same crono, all things equal. I don't consider the schueman defective, just not as fast. I will do this and report back. Thanks everyone for all the suggestions. Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted July 11, 2012 Share Posted July 11, 2012 How is accuracy in each gun? Accuracy is seems to be fine, but all the shooting in the KKM pro barrel has over the chrono so far. If there's a big variation in velocity, I'd expect to see some vertical stringing?? Be worth checking out - I like the idea of using factory ammo, too - great idea - and check velocity & accuracy. Link to comment Share on other sites More sharing options...
Yagi Posted July 11, 2012 Share Posted July 11, 2012 how many bullets did you load for each grain setting? what kind of powder weighing device are you using? 3.6 and 3.7 is not too far when using a balance scale...Sometimes even when using an electronic weighing scale it will still throw you off since the powder throw at times will not be exactly precise. In my opinion i would send KKM a letter explaining what you are experiencing but i would test further before sending it back... How is the accuracy between the stock and kkm? Link to comment Share on other sites More sharing options...
rhyrlik Posted July 15, 2012 Share Posted July 15, 2012 How does the KKM barrel fit? There could be a headspace issue. For one, if the chamber is too long, the case is headspacing off the extractor hook. That is bad for ignition which would explain your huge ES. Link to comment Share on other sites More sharing options...
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